1. Field of Invention
The invention relates to shielding apparatus for rotating shafts which serve as safety guards and/or covers to prevent the ingress of dust and dirt into rotating parts. In particular the invention relates to the shielding of rotating shafts on vehicles such as drive shafts which serve to transmit torque from an engine. The invention also relates to a method of assembling a shielded shaft of the kind described above.
2. Description of Related Art
Guards are often provided on the outside of vehicles to prevent operators coming into contact with moving parts on safety grounds. This applies to rotating drive shafts which are present on the underside of many vehicles, such as agricultural tractors, wherein torque is transmitted from an engine to a gearbox or from a front axle to a rear axle for example. Health and safety legislation in a number of jurisdictions dictate that guard apparatus must be provided as a necessity.
In addition to improving safety the guard can also serve to reduce exposure of the shaft to dust and dirt. In the case of agricultural tractors the guard may shield a drive shaft from windrows of hay which may come into contact with underside of the tractor. Without the guard in place hay may become wrapped around the drive shaft eventually leading to failure thereof.
FIGS. 1, 2 and 3 show a known shaft shielding assembly fixed to the underside of a tractor. A drive shaft 12 extends longitudinally underneath the frame 14 of the tractor between the rear axle (not shown) and the front axle (also not shown). The drive shaft 12 delivers torque from the rear axle to the differential of a front axle to provide four-wheel drive.
The guard element 16 is of substantially U-shaped construction and is bolted by bolts 17 to the underside of the frame 14 or to the rear axle and thereby being secured in position. A window 18 is provided in the underside of the guard 16 to prevent build up of dust in the channel
The guard element 16 is secured in position at a late stage of assembly to enable easy access to the drive shaft and surrounding components.